NoClassDefFoundError: com.ibm.websphere.crypto.PasswordUtil even after enabling ibm-spi

I have included apiTypeVisibility="ibm-spi,spec,user,ibm-api" (that is, default + ibm-spi) in my application's classloader-element in server.xml, yet I get NoClassDefFoundError: com.ibm.websphere.crypto.PasswordUtil when I start my application.

Is there anything else I have to do? Do I need to enable a certain feature to access containerServices (which contains PasswordUtil)?